The statements in this section merely provide background information related to the present invention and may or may not constitute prior art.
In a photolithography process for manufacturing a semiconductor device such as TFT-LCD modules, photo resist is coated on a substrate by a slit nozzle generally. The slit nozzle has a slit outlet as a discharge opening for a coating fluid material. The slit nozzle moves above the substrate and applies the coating fluid material (such as colour filter resist) on the substrate. The colour filter resist usually contains pigments dispersed therein. On the other hand, the opening width of the slit outlet is usually small (about 100 microns). In coating process, the slit outlet may be blocked and thus the quality of coating will be affected adversely.